Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates generally to lift cranes
and more particularly concerns a mobile concentric ring
supported crane.
In response to ever-increasing user needs, self-
propelled cranes have been made capable of lifting ever
greater loads. While a number of factors enter into
determining crane capacity, a basic limitation arises from
the fact that, inevitably, the weight of the crane and its
load must be transferred to the earth in some stable fashion
and, if rotation of the load is desired, the crane-earth
connection must be made stable through the arc of crane
rotation.
A significant increase in crane capacity was
achieved by providing a self-propelled crane with the support
ring and extended boom carrier disclosed and claimed in U.S.
patent Nos. 3,485,383 and 3,878,944. In this design, the
weight of the crane and its load is transferred to the ground
through a large diameter, track-like ring. As shown in these
patents, and as practiced commercially for some years, the
support ring is either blocked into place by timbers fitted
and wedged beneath and completely around the ring or is
supported by a plurality of jacks spaced around the periphery
of the ring.
Further refinements in ring supported cranes are
disclosed in U.S. patent Nos. 4,042,115 and 4,103,783 and
copending Canadian applications Serial Nos. 345,094 and
345,096, both filed June 16, 1980. These patents and
applications disclose inter alia that a separate transporter
mechanism may be run in and out of an otherwise stationary
ring supported crane in order to move that crane between
different locations or transporter mechanisms and~or idle
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crawlers or dollies may be installed beneath the ring under
the boom foot and counterweight.
The primary aim of the present invention is to
provide a heavy lift crane assembly having an upper structure
including a forwardly inclined boom and a rearwardly inclined
ma8t pivotally mounted on a boom carrier mechanism with rigging
means interconnecting the tip of the mast and the tip of the
boom, counterweight means supported by rollers on a rear
ring segment for rotation about a vertical axis and means
interconnecting the counterweight and the top of the mast,
characterized by the boom carrier being supported by rollers
on a separate front ring segment for at least partial
circumferential rotation about the vertical axis and including
front and rear mobile support mechanisms respectively located
under the front ring segment and under the rear ring with
means interconnecting the front and rear support mechanisms
to permit movement of the crane as a unit.
Figure 1 is a side elevation of the concentric
ring segment supported lift crane of the present invention;
Fig. 2 is a section taken substantially along
line 2-2 in Fig. l;
Fig. 3 is a fragmentary front elevation of the
crane shown in Fig. 1 with a single boom illustrated in solid
lines and dual booms illustrated in bro~en lines; and,
Fig$. 4 and 5 are fragmentary side elevations,
similar to Fig. l, of two alternative embodiments of the
invention.
Turning now to the drawings, there is shown in
Figure 1 the concentric ring segment supported lift crane 10
of the present invention. The crane 10 includes a rear
machinery and counterweight support mechanism 11 and a front
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boom and mast support mechanism 12. In the illustration of
Figure 1 the machinery and counterweight support mechanism
11 includes a large diameter ring 13 supported by a substan-
tially rectangular frame 14 on a self propelled transporter
mechanism 15 substantially as disclosed in U.S. patent No.
4,195,740. Suffice it to say that the ring-like track 13
is on the order of 36 feet in diameter and the lift machinery
16 and counterweight 17 are supported on a rotatable deck 18
for movement about the ring center line designated A.
The front boom and mast carrier mechanism 12 includes
a carrier 20 supported by rollers 21 on a front ring segment
23 which is concentric with the axis A of the rear ring 13.
The carrier 20 pivotally mounts a forwardly inclined boom 25
and a rearwardly inclined mast 26. The tip of the mast 26
is connected to the tip of the boom 25 by variable length
rigging 27 whiçh includes a multiple part line wound on a
boom hoist drum 28 located on the machinery deck 18. The
upper end of the mast 26 ia also connected by means of a
fixed length pendant or strut 29 to a gantry 30 carried on
the machinery deck 18. In this way the counterweight 17
is connected to the mast top and through the rigging 2~ i8
applied to the boom tip to counteract the moment of a heavy
load.
In the configuration shown in Figure 1 the crane 10
includes a primary lift line 32 wound on a winch drum 33 and
reeved around guide sheaves 34 and 35 and a boom tip sheave
37. The boom 25 is also provided with a jib section 38
supported by guy pendants 39 and a strut 40. An auxiliary
lift line 41 is wound on another drum 42 ana is guided by
sheaves 43 and 44 to the tip (not shown) of the jib 38.
Pursuant to the present invention the front boom
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support mechanism 12 is carried on a transporter assembly 45
interconnected by a frame element 47 to the rear machinery
transporter 15. The front transporter 45 is preferably a
demountable self propelled assembly such as shown in U.S.
Patent Nos. 4,000,784 and 4,069,884. It will be appreciated
that by suitabl~ controlling the front transporter assembly
45 and the rear machinery transporter 15 the crane 10 may
be moved over the terrain in either a loaded or an unloaded
condition.
~ In keeping with another aspect of the invention, the
boom carrier 20 is rotatable on the front ring segment 23 in
order to swing a load through at least a partial horizontal
arc. Swinging movement may be provided through a web-like
strut 48 connected to the rear machinery deck 18, and the
front carrier 20 or, alternatively, the carrier 20 may be
rotated on its ring segment 23 by one or more independent
swing drive mechanisms such as shown in U.S. Patent No.
3,949,881 and 4,013,174.
As ~hown in Fig. 2, a pair of front transporter
assemblies 4S are provided to support the ring segment 23.
Each transporter 45 carries a pivot ring 50 on which a base
plate 51 is mounted. This permits the transporter mechanisms
45 to be propelled, as disclosed in U.S. patent No. 4,069,884
to move in forward, reverse or turning directions (the latter
being shown in broken lines). Since the transporters 45
support the ring segment 23 on which the boom carrier 20
rides, the crane 10 may move under either loadea or unloaded
conditions.
According to the present invention , heav~ lifts
and placement of loads can also be made which require swinging
the load through a substantial arcuate segment, for example
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90 or more. This is particularly useful in making multiple
lifts of loads from a carrier, such as a ship or barge and
placement of the loads on a dock or pier. Accordingly, as
shown in dash lines in Fig. 2, additional concentric ring
segments 23a, b and c may be attached to the primary ring
segment 23, and these additional ring segments 23a, _ and _
may be blocked or jacked into level position such as by the
bolsters shown at 53a, _, _ and _.
It will be appreciated, of course, that a single
boom 25 may be supported by the front carrier 20 las shown in
solid lines in Fig. 3) or spaced-apart dual booms 25a and _
may be provided ~as shown in broken lines of Fig. 3). In
the latter instance it is desirable to provide dual ~rans-
porter mechanism 45, while a single front transporter may be
sufficient if a single boom 25 and only limited swinging of
the load is contemplated for a particular lift.
Turning now to Fig. 4, another embodiment o the
heavy lift crane is illustrated. As shown here, the rear
lift machinery and counterweight support is substantially the
same as that disclosed in copending Canadian application
Serial No. 345,096. Otherwise, this unit is generally
similar to that shown in Fig. 1 and similar reference numerals
are used for similar parts.
In Fig. 5 another embodiment is shown based on an
enlarged 60 foot rear ring mounted on self-propelled trans-
porters 15a and _ (which may be single or dual units) similar
to the transporter 45 in Fig. 1. The basic ring structure
and machinery deck for the embodiment of Fig. 5 may be
substantially the same as that disclosed in U.S. Patent
No. 4,103,733 as modified by the addition of the transporter
assemblies 15_ and b. In other respects reference numbers
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similar to Fig. 1 are employed.
It should also be appreciated that the embodiments
shown in side elevation in Figs. 4 and 5 may employ either
single or dual front transporter assemblies 45 (as shown in
Figs. 2 and 3) and either single or dual booms 25 (as shown
in Fig. 3). Likewise additional concentric ring segments
23a-x (as shown in Fig. 2) may be attached and supported by
blocks, bolsters, jacks or the like.
From the foregoing, it will be seen that a heavy
lift crane is provided utilizing a standard "Ringer" crane
as the rear lift machinery and counterweight support and a
front concentric ring segment for supporting the boom and
mast and transmitting the load down through a self-propelled
transporter assembly into the ground.
